The present invention pertains to conveyor belt systems for turning over printed products.
Magazines, books, periodicals, newspapers, and other similar printed products, referred to herein as signatures, are commonly discharged from a binding or similar machine and conveyed along a path of travel to a stacker or other processing station. Depending upon how the covers of the signatures are designed, the publisher may want to place labels on either the top or the bottom surfaces. To provide this option, it is desirable to be able to turn over the advancing signatures, so that a label applying unit which is at a fixed location can be utilized.
Conveyor belt systems for turning over printed products are known. For example, U.S. Pat. Nos. 3,729,189; 3,838,771; 4,226,324; 4,569,620; 4,669,715; 5,540,318 and 5,988,352 each disclose conveyors for contemporaneously conveying and rotating printed products through 180xc2x0, so that the products are turned over. For these patents, the products are rotated about an axis that extends in the direction of travel, and the direction of travel is horizontal. As a result, the conveyor systems can be characterized as occupying a relatively large amount of floor space, which can be disadvantageous in many circumstances.
In contrast, U.S. Pat. No. 4,364,463 discloses a conveyor that turns over newspapers by rotating the newspapers about an axis that extends in the direction of travel, with the direction of travel being vertical. However and disadvantageously, this patent does not disclose that a turned over newspaper can be conveniently and efficiently returned to the same conveyor from which it originated.
Accordingly, there is a need for a conveyor belt system that is capable of turning over signatures while occupying a relatively small amount of floor space, and that is preferably further capable of lifting the signatures from and depositing the signatures onto the same conveyor, with the signatures being turned over when they are deposited and each signature preferably being deposited onto the same moving station from which it was lifted.
In accordance with one aspect, the present invention advantageously solves the above and other problems by providing a turning apparatus having a conveyor system for lifting advancing signatures from a conventional conveyor, conveying the lifted signatures along an upright path of travel, turning the advancing signatures from the upright path of travel to a downward path of travel, depositing the advancing signatures from the downward path of travel back onto the conventional conveyor, and rotating the advancing signatures 180xc2x0 about an axis which is parallel to their path of travel during either their upward path of travel or their downward path of travel so that the signatures are turned over when deposited back onto the conventional conveyor. According to this aspect, the turning apparatus is advantageously capable of occupying a relatively small amount of floor space and is further capable of lifting the signatures from and depositing the signatures onto the same conventional conveyor. The conventional conveyor can be characterized as having multiple moving stations, and preferably the signatures are respectively returned to the same moving station from which they were lifted.
In accordance with another aspect of the present invention, the conveyor system includes a driven central belt having an upright upstream flight for engaging and conveying the stream of signatures in an upward direction, and an upright downstream flight that is downstream of the upstream flight in the stream of signatures and is for engaging and conveying the stream of signatures in a downward direction. One of the flights has a twisted section that is twisted substantially 180xc2x0 about an axis parallel to the flight. In accordance with this aspect, the conveyor system has another driven belt having a section that is twisted substantially 180xc2x0, runs in face-to-face relation with the twisted section of the central belt, and is for engaging and conveying the stream of signatures so that the twisted sections of the belts cooperate to twist the stream of signatures substantially 180xc2x0 while together conveying the stream of signatures.
In accordance with another aspect of the present invention, the central belt further includes a generally horizontal intermediate flight for engaging and conveying the stream of signatures between the upstream and downstream flights of the central belt.
In accordance with another aspect of the present invention, the turning apparatus can advantageously be bypassed by manipulating inlet and outlet diverters, so that the signatures advancing along the conventional conveyor are not turned over by the turning apparatus. The inlet diverter is for lifting the signatures from the conventional conveyor, and the outlet diverter is for depositing the signatures onto the conventional conveyor.
In accordance with another aspect of the present invention, one or more of the belts include a return flight that is not for conveying signatures. The return flight defines a convolute path having portions extending perpendicularly from a plane defined by the path of travel of the signatures, so that the size of the turning apparatus can advantageously be minimized.
In accordance with another aspect of the present invention, the conveyor system includes a variably sized nip through which the signatures pass. A sensor is provided for detecting when the nip has become too large, such as a result of being jammed with signatures. The system is advantageously automatically shut down when the sensor detects a jam. A mechanism is provided for adjusting the size of the nip so that the turning apparatus can accommodate signatures of different thickness. In one example, an adjustment mechanism that is advantageously remote from the nip can be operated to adjust the size of the nip, and structure is provided to emulate the size of the nip at the adjustment mechanism, so that the nip can be accurately remotely adjusted.
Aspects and advantages of the present invention in addition to those described above will be apparent to those of ordinary skill in the art upon studying the following descriptions and associated drawings.